Validated green high performance liquid chromatographic and capillary electrophoretic methods for estimation of dinitolmide in presence of its acid-degradation product

Abstract

This study describes two new, green, fast, specific and highly sensitive stability-indicating techniques for determination of Dinitolmide (DM) in presence of its acid induced degradation product without prior separation; Acid degradation was carried out by hydrolysis with 0.1 N HCl; and the acidic degradation pathway was established by IR, and MS techniques. The first is a HPLC-Diode Array detector was performed by isocratic mode on BDS Hypersil C18 column (150 mm × 4.6 mm × 5 μm particle size) at ambient temperature with a mobile phase consisting of 5 mM sodium acetate buffer (pH 5.5): acetonitrile (40:60, v/v), flow rate of 1 mL/min and detection at 210 nm. DM and its acid degradant were eluted at 4.3 and 2.8 min, respectively offering quick analysis. Linearity of the calibration curves confirm good correlation in range of 1–15 μg/mL with recovery % of 100.02 ± 0.460. The LOD and LOQ were 0.243 and 0.737, respectively. The second method is CE -Diode Array detector was carried out at 25 °C using borate buffer (30 mM, pH 9) as background electrolyte solution and detection at 225 nm. The migration times were 2.26 and 2.97 min for DM and its acid degradant, respectively. The linearity range was 5–50 μg/mL with recovery % of 99.55 ± 0.910, LOD and LOQ were 1.010 and 3.050, respectively. The small LOD and LOQ values for both methods confirm high sensitivity of the methods The developed methods were validated according to the ICH guidelines demonstrating good accuracy and precision. The results were statistically compared with those obtained by a reported method in terms of accuracy, precision, and no significant difference was found. Both methods were successfully applied for estimating DM and its acid degradant in pure and pharmaceutical dosage forms. In addition, the methods were assessed for their greenness profile and CE was greener owing to using safer solvents and less energy consumption.